Apparatus for treating petroleum



Nov. 20, 1945. D. w. sTlLwELL 2,389,328

APPARATUS vFOR TRETING PETROLEUM Filed May 18, 1942 2 Sheets-Sheet l y INVENTOR Arroz/vsn Nov. 20, 1945. D. w. sTlLwELL 2,389,328

' APPARATUS FOR TREATING PETROLEUM Filed May 18, 1942 2 Sheets-Sheet 2 .Q4 v/D W .Sr/L WEL L, INVENTOR ATTORNEY.

Patented Nov. 20, 1945 UNITED STATES PATENT GFFICE APPARATUS FOR TREATING PETROLEUM David W. Stilwell, Los Angeles, Calif. Application May i8, 1942, Serial No. 443,409

4 Claims.

My invention relates to the treatment of oil, primarily crude petroleum, the principal object being the removal f Water, sand, emulsion, and foreign matter generally.

This has previously been accomplished in several ways, as for example (a) breaking down the viscosity by heat or solvent, and (b) useA of chemicals. Prior methods involve various disadvantages well known in the art. The purpose of breaking down the viscosity is to allow f reign matter, which is heavier than oil, to drop, and the Washed oil to ow over into tanks or elsewhere for further handling.

The prior methods under example (a) which utilize heat, employ hot water or steam for heating the body of crudeV to be washed. Ii the temperature of the Water exceeds 212 F., a back pressure of 60 to 100 lbs. must be maintained to keep the water liquid. The use of steam involves higher pressures. Any water or steam system is subject to pressure, requiring a circulating system of sufficient strength to withstand high pressures, and generally complicating the system, requiring constant and skillful attention during operation. The system is also subject to oxidation and other deteriorating effects, and subject to the danger of a split line, broken fittings, and blow up, and the danger of burning or otherwise injuring Workmen.

An object of my invention is to provide a method of washing oil in which the heating element is a highly rened lubricating oil. Among other advantages, this has the following:

l. There is only atmospheric pressure on the system.

2. The heat transfer of oil is aboutY twice as efficient as water or steam, thus reducing fuel consumption.

3. There is no oxidation or other deteriorating eiiects on the apparatus.

4. The system may be virtually automatic, requiring a minimum of attention.

Another object is the provision of a novel form of wash tank in which increased efficiency is realized.

These, and other objects of my invention, will be made more apparent upon consideration of the description and claims.

In the drawings:

Figure 1 is a diagrammatic plan View of an apparatus suitable for carrying out my improved method.`

Figure 2 is a diagrammatic elevational view of the same.

Figure 3 is a vertical cross section of my novel wash tank indicated in Figures 1 and 2.

Figure 4 is a fragmentary bottom view of the separator plates and distributing heads in the wash tank, as seen on the line 4-4 of Figure 3.

Referring to Figures l and 2, an apparatus suitable for performing my method may comprise a gas line I0, a scrubber Ii, a gas regulator I2, a solenoid gas valve I3, a thermostat I4, and a gas heater I5, for heating the lubricating oil which is carried in the oil line IS.

The heater includes a burner I'Is and coils I8 in staggered relation as illustrated, or any other desired arrangement. These coils form an element in the oil line I6, which. as will become apparent, is a re-circulating system.

At suitableV locations in the oil line I6 are a pump I9 and a surge tank 20. I may also provide an overow tank 2l, and thermometers 22 and 23 in the hot oil and return sections respectively, and a pressure gage 24.

The oil line includes one or more coils (later described) in a wash tank 26. In contemplating my method, any form of coils and Wash tank may be employed, it being essential only that the coils be located in a suitable tank within the region occupied by a body of petroleum to be treated, the tank affording a receiving chamber for the petroleum to be treated, a space or settling chamber wherein Water, sand, emulsion and other foreign matter may gravitate, and a temporary storage chamber with preferably a discharge overilow for taking off treated oil. Such features, and additional details are shown in Figures 3 and 4, and will be more fully described in connection with my novel form of wash tank.

In practicing my method, a highly rened lubricating oil is heated to the desired temperature (ordinarily about 250 to 275 F.) in the heater I5, and delivered through the oil line i6 in the direction of arrow 2l (Figure 2) to the coils in the wash tank, circulated therethrough, and returned to the surge tank 20. A heat exchange takes place within the wash tank, the lubricating oil giving up its heat through the coils to theV body of crude Within the tank, breaking down the viscosity of the crude, and allowing foreign matter to settle out. The lubricating oil re- From the surge tank, the

lubricating oil is drawn by the pump I9, and pumped through the coils I8 in the heater for reheatingand recirculation.

There is no requirement for any pressure on the oil line I6, because oil of the character employed may be heated at atmospheric pressure to any temperature necessary in a system of the character described without vaporizing. It is Y' possible with my method, to eliminate the pump, but in the interest of eiciency a forced circulation is preferred.' Y

In a sense the oil line I6 is a closed circulating system, but I intend to convey the thought of Vcontinuous recirculation, notin the presence of any elements which might create a back pressure.

2|. 29, and a vent 38. and eliminate any tendency to back pressure in the line, or vaporlocks. An overflow line 3i carries offrexcess` oil from the surge tank into the overow tank, so that waste of oil is avoided.

The oil used as theheating medium must be specially prepared.Y It must be a highly rened lubricating oil from which foreign matters have been-removed, and must be treated with a mechanical wash, as for example, forcing it through filters. An acid Vequalizer can be used in place of a mechanical wash, but if conditions are not exactly right, the resulting oil will sludge up under use. Forconsistently good results, the mechanical wash should be used.

Lubricating oil, so prepared, furnishes a heating medium which is efficient, and can be recirculated indefinitely without -its Ydesirable characteristics changing. It absorbs heat faster than Water and gets rid of it quicken-being about twice as ecient as water or steam, and therefore.

more economical on fuel; n I

So far as I am aware, I amthe first to'use oil as a, heat transfer agent for reducing the viscosity ofcrude in a Washing or treating operation.

2.By my method, thebody of crude in the washing.v tank may be maintained at the desired tem-- senceof my method invention resides in circulat ing (a highly refined heated lubricating. oil

vertical `sides 6Ik of increasing relative height toward the outer end, a top 62 extending from the wall of chamber 54, and an outer end closure 63 My oil line may be open to the atmosphere, as v illustrated in the surge tank 2U and overflow'tank The surge tank is providedwith a ll spout The vent is to take oi vapors,

covering the upper half of the end opening. The

sides and end closure are formed with slots 64.

A second coil 65 is located Within the chamber 54. This' coil is' aY vertical type, and is a part of the oil line I 6 .which includes coil 52.

A tank outlet 66 provides for overow of treated petroleum to storage or shipping tanks. .Y In operation,` crude oil to Ybe washed passes in through the inlet53. Ordinarily `the :crude will have vbeen passed through a gas separator (not shown), so that in the wash tank substantially gas free petroleum-is to.l be treated for. the r'emoval of water, sand and other impurities.

A heating medium such as the highly rened nlubricating oil previously described-heated to the desired temperature, is passed vthrough the oil line I6, including coils n52 and65. g

Theiincoming crude oilY is initiallyheated in the vchamber 54, bythe exchange of v,heat from the coil 65. The viscosity'isbroken down. Any gas freed will rise andV be disposedof by anyconventional means desired. The heated .crude oil will be distributed by the separator plates 58 and distributing heads 59 linto the cone 43. The heavier foreignrelements will tend VVto'pass with the oil Vthrough the end openings, and the kremainder of the voil will pass in ribbon ,form through, the slots 64 inthe sides 6| and ends 63. The foreign matter will accumulate byV gravity in the lower part of the cone, andmay be continuously or periodically drawnoffthrough a pipe 61 andmvalve V68 assisted if desiredL by a. pressure lldiet The Crude. oil, rises .into the., drum, the4 bull;v o f it flrstvenountering thespreader cones 56 and 51 passing through the slots 53,. lt. enters the drum, and passes through vthe screens41 for the further removal of any foreignA matter, and into, the tank Q11tempgrarvsterageChamber lathe;

petroleum in which `is-rnaintained hot by `thecoil through a conductor in a bodyYof-crude to break 4 down the viscosity ofthe crude and allow foreign matter to-gravitate therefrom.

Referring to Figures 3 and 4, my novel washing tank 26 comprises a shell4ll suitably mounted on a concrete or other base 4 I. Also mounted von the base 4I is a frame 42 which supports a cone 43 forming a settling chamber. A shelf 44 abutting the upper edge of the cone, rests upon the shell 40, and a temporary storage ltank wall 45' rises from the shelf 44. A drum 46 provided Ywith screens 41 rests upon the upper edge of the cone, and is formed with a cover 48. vertical Vangle irony supports 49, welded at. the bottom to brackets 50, and at the top to brackets 5I,'a1'e thus located adjacent the outer surface of the drum 46, and support -the convolutions cf,

pipe forming a'coil 52 surrounding the drum.

A crude oil inlet 53'empties into a central ref` ceiving chamber 54, the cylindrical-walls-forming A plurality `Of` 52, to aid in"maintaining the ychamber 54 heated, and to -assist the flow of treated petroleum through the .outlet 66 to storage or shipping faci11ties. Having described my invention, what I claim as new and desire to secure by Letters VPatent is:

l`.'A petroleum' Wash tank, comprising a receiving chamber, vertical"heatingl kcoils'therein,v distributing `heads extending outwardly from said chamber, spreader iconesr extending Vfromf'said chamber and overlying Vthe distributing heads,` ra

` cone below the chamber to'receve foreign matter passing downward through petroleum Ain the chamber, anda passage permitting the-flow'of petroleumout of said cone. Y Y Y i 2. A petroleum washltank comprising? a receiving chamber, vertical heating' coils atherein, distributing heads extending outwardly fromsaid chamber, spreader cones extending from. said drum embracing the lower end of thereceiving chamber and the upper end of the cone, ra cone below the chamber to receive foreign matter passing downward through petroleum in the chamber, and a passage permitting the flow of petroleum out of said cone.

3. A petroleum wash tank comprising: a receiving chamber, vertical heating coils therein, distributing heads extending outwardly from said cham-ber, spreader cones extending from said chamber and overlying the distributing heads, a drum embracing the lower end of the receiving chamber and the upper end of the cone, said drum being provided with screens, a cone below the chamber to receive foreign matter passing downward through petroleum in the chamber, and a passage permitting the flow of petroleum out'of said cone. Y Y

4. A petroleum wash tank comprising: a receiving chamber, vertical heating coils therein, distributing heads extending outwardly from said chamber, spreader cones extending from said chamber and overlying the distributing heads, a drum embracing the lower end of the receiving chamber and the upper end of the cone, heating coils around the drum, a cone below the chamber to receive foreign matter passing downward through petroleum in the chamber, and a passage permitting the flow of petroleum out of said cone.

DAVID W. STILWELL. 

